Steam-feed for saw-mills



(No Model.) l 3 sheetssheet 2.

DE WITT C. PRBSCOTT. STEAM FEED FOR SAW MILLS.

No. 360,972. PatentedApr. 12,1887;

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, DE WITT C.` PRESGOTT.

STEAM EEED EOE SAW MILLS. No. 360,972. Patented Apr. 12, 1887.

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UNITED STATES PATENT OFFICE.

DE WITT CLINTON PRESCOTT, OF MARINETTE, WISCONSIN.

SPECIFICATION forming part of Letters Patent No. 360,972, dated April12, 1887.

. Application filed August 2, 1886. Serial No. 209,798. (No model.)

To all whom t may concern.'

Be it known that I, DE WITT CLINTON Pans- OOTT, a citizen of the UnitedStates, and residing at Marinette, in the county of Marinette' and Stateof Wisconsin, have invented a certain new and useful Improvement inSteam- Feedfor Saw-Mills,which is fully set forth in the followingspecification, reference being had to the accompanying drawings, inwhich-` Figure 1 represents a front elevation of 'the saw-frame,saw-carriage, and steam-feed embodying my improvement; Fig. 2, a sideelevation of the same, partly broken away; Fig. 3, a verticalsection ofthe same, taken on the line w a', Fig. 2; Fig. 4, a vertical section ofthe valve and valve-chest belonging to the steam-feed; Fig. 5, asectionof the same, taken on the line y y, Fig. 4; and Fig. 6, a similarsection taken on the line z z, Fig. 4. These figures of the drawings areon different scales, Figs. 1, 2, and 3 being onone scale, and Figs. 4,5, and 6 on another and very much enlarged scale. I My present inventionrelates to yband-saw mills. Band-saws have been applied successfully toordinary saw-mills for cutting up logs within a comparatively recentperiod. With modern improvements, however, this kind of saw is now insuccessful use for sawing logs, and is growing in favor with saw-milloperators. In 1876 Letters Patent No. 174,004, dated February 22, weregranted to me for a steam feed mechanism for saw-mills, which patent wasreissued April 9, 1878, N o. 8,160.

The object of my present invention is to apply a steam feed device to aband-saw mill.

The saw-mill, which is represented in the drawings, or at least suchparts of the bandsaw mill as are there shown, is the subjectmatter of aseparate application filed by me July 3, 1886, Serial No. 207,142, towhich reference is made for full information.

Inthe present case it is not necessary to describe all the parts of themill, and, indeed, I have not shown all in the drawings, only thosebeing illustrated which are essential to au understanding of thepresentimprovement, and Ishall only briey refer to these parts.

The steam feed mechanis'm is in all general features like that describedand shown in my prior patent, Reissue No. 8,160,0f April 9, 1878, towhich reference is here made for a full description. I shall heredescribe only such parts as are necessary to understand its applicationto the band-mill.

I will now proceed todescribe such parts of the mill as are necessary toan understanding of the construction and operationof the mechanism bywhich I have embodied my invention practically in one way, and will thenpoint out denitely in the claims the special improvements which Ibelieve to be new and wish to protect by Letters Patent.

In the drawings, Arepresents the saw-frame, which is upright, as usualin this class of saws, and is mounted upon timbers A of the iloor. Atthe upper end Of the frame is the upper band-wheel, B, and below theframe is the like lower wheel, B. plied to these wheels in the usualmanner, and guides c are arranged on the working side of the frame aboveand below the log for-the purpose of steadying the saw. The log-car-'riage D is of any usual construction, and is mounted in the ordinarymanner upon tracks d, on which the truck-wheels d of the carriage run. Asteam-cylinder, E, is arranged below the log-carriage in the usualmanner for the application of my patented steam feed mechanism. rIhiscylinder is provided with a piston .which is connected to the carriage,the general arrangement and operation of these parts being as set forthin the patent, Reissue N o. 8,160.

A steam-chest, F, is below the carriage and cylinder, and is suppliedwith steam by the supply-pipe G, coming from the boiler. Feedpipes H andH lead from the steam-chest to the front and rear ends, respectively, ofthe Asteam-cylinder, thereby providing for the admission of steam to thelatter on either side of the piston, as may be required. Ihave foundthat the usual way in which I operate this steam feed mechanism inconnection with circular saws will not answer for /band-saws. Heretoforethe' valve employed has been of such construction as to let on the steamat once to feed the carriage up to the saw, thus bringing the log to thesaw and driving it through with full force. .I have found that this willnot answer for a band-saw. The carriage for a band-saw'must be handledwith great care and with varying speed, according to circumstances.Sometimesinlarge logs the carriage The band-saw C is apy should barelymove along; but its speed may be increased as the log is worked down, orwith smaller logs. The control of the carriage must be perfect andcapable of regulation to a considerable degree of nicety. I havetherefore devised an improvement to the valve mechan ism by which thissteam-feed is made applica ble to band-saw mills, to which it could nototherwise be applied. The steam-chest F is provided with ports g for thesupply-pipe, and h it for the respective feed-pipes to the cylinder.This chest is constructed substantially as shown and described inLetters Patent No. 215,293, granted to me May 13, 1879, to whichreference is made for a more complete description. A sleeve, I, ismounted in the valvechest within the port h, through which steam isadmitted to the front end of the cylinder for feeding the carriage tothe saw for work. The valve J', which is of similar construction to thatshown in my prior patent, just mentioned above, plays through thissleeve--that is, the inner end of the valve is arranged within thesleeve, as seen in Fig. 4 of the drawings, and reciprocates therein.Openings are made through the sleeve into the port. These openings arepreferably of triangular shape, arranged with the apex pointing inwardtoward the valve, and some of them, i, are long enough to' extend quiteacross the port, while others, i', are 'much shorter. If preferred,however, they may all be of the same length and extending across theport, or substantially so. Any other form may be given tothese openings,provided they are constricted toward the valve.

The valve J is constructed substantially as in Patent No. 215,293, beingcylindrical, and provided with openings]l andj. In Fig. 4 of thedrawings the valve is shown in position after the carriage has beengigged back and is ready for its forward movement toward the saw. It isevident that if the valve is now thrown over toward the port h the steamescaping from the openings j into the latter must pass through theopenings i and z" in the sleeve I, and the portions of these openingsfirst uncovered will be the narrow parts of the openings t'. Obviously,therefore, at the irst the supply of steam to the feed-pipe H will besmall, in fact, just enough to start the carriage. As the valve is movedby the attendant, this supply will be gradually increased by theuncovering more and more of the openings i, and finally of the shorterones, i', as the valve moves past them. The movement of the carriageunder this operation may be regulated so as to move very slowly, or atany speed desired up to that produced by the full force ofsteam intendedto be supplied through this feed-port. The carriage is completely underthe control of the attendant, who can regulate its movement with greatnicety. All danger of injuring the saw is in this way obviatcd, and thesteam feed mechanism is made perfectly practical and operative forband-saw mills, and performs the same efficient work with practicallythe same advantages as it does in circular mills. In order to operatethe valve, it is connected by a rod, K, with a crank, it, ona'rock-shaft, L, the other end of which is provided with a crank-arm, Z,to the outer end of which a hand-lever, M, is connected by the link m..The mechanism is thus placed under the control of the attendant orsawyer, who manages it by working the lever M, whereby he moves thevalve as deslred.

The operation and construction of the port h and the valve-openings jare substantially as in my former patent, referred to above, as there isno necessity for graduating the movement of the carriage backward. Theexhaust is also the same, the chest being provided with an exhaust-port,a, leading to an exhaustpipc, N, which is connected therewith.

The sleeve device described above is especially adapted to theparticular' kind of valve here shown, which is cylindrical and balanced.It is not absolutely necessary that this particular variety of valveshould be used with my steanrfeed, though I have found it preferable toothers. It will be necessary, however, if a valve of any otherconstruction is used, to provide a device for regulating or graduatingthe passage of steam into and through the port corresponding to the portIt in this instance, and this may be effected by a device similar to thesleeve here shown, the form and shape of the latter being changed toadapt it to the particular form of valve and port which is employed. Insome instances, however, it may be necessary to provide a deviceconstructed or arranged very differently, but still admitting the steamgradually to this port, or to the feed-pipe corresponding thereto. Somedevice of this nature will be found necessary with the feed operating inconnection with a bandsaw.

I do not wish to bc understood as limiting myself to the details ofconstruction herein shown and described above, for, as already stated,there may be changes in the vital part ofthe mechanism, and, obviously,changes may be made in other parts which have been mentioned above to avery great extent without departing from the invention herein set forth.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a saw-mill, a band-saw, in combination with the log-carriage, asteam feed device connected to thc carriage, and a graduating device,whereby steam is admitted to the cylinder gradually for the forwardmovement of the carriage, substantially as and for the purposes setforth.

2. In a saw-mill, a bandsaw, in combination with the log-carriage, asteam feed device connected to said carriage, a valve for admittingsteam alternately to the feed-pipes leading to the front and rear of thesteam-cylinder, and a device covering the portopening to the former ofsaid pipes, and provided with graduated openings, whercby steam issupplied in small quantity atfirst and gradually increased,substantially as and for the purposes set forth.

IOO

3. The saw-carriage, in combination with the steam-cylinder, pistonarranged therein, feed-pipes opening into the cylinder in front and rearof said piston, steam-chest provided 5 with ports h la', reciprocatingValve J, and sleeve I., provided with openings gradually constrioted asthey extend inward, substantiaily as and for the purposes set forth.

4. The saw-carriage, in combination with Io the steam-cylinder andvpiston, the feed-pipes' H Hf, the valve-chest F, provided with ports hh', the reciprocating valve J, yprovided with openings j j, and thesleeve I, provided with tapering openings 'i i', the latter shorter thanthe former, substantially as and for the pur- I5 poses set forth.

DE WITT CLINTON PRESCOTT.

Witnesses: Y

W. P. MARS, JOHN J. ANDREW.

